package rtcconformance

import (
	"bytes"
	"crypto/sha256"
	"encoding/hex"
	"encoding/json"
	"errors"
	"fmt"
	"io"
	"regexp"
	"slices"
	"strings"
	"time"
)

const (
	CaptureSchema   = "real-device-rtc-capture-v1"
	ReportSchema    = "real-device-rtc-conformance-report-v1"
	MinimumDevices  = 3
	MinimumSessions = 6
)

var digestPattern = regexp.MustCompile(`^sha256:[0-9a-f]{64}$`)
var RequiredEngineModes = []string{"s2s_pure", "s2s_hybrid", "cascade"}
var RequiredScenarios = []string{"NORMAL_COMPLETION", "TOKEN_RENEWAL", "NETWORK_SWITCH_RECOVERY", "CONTROLLED_STOP"}
var RequiredLifecycle = []string{"ROOM_ISSUED", "STARTING_AGENT", "ACTIVE", "STOPPING", "COMPLETED"}

type Capture struct {
	SchemaVersion     string            `json:"schema_version"`
	EvidenceSource    string            `json:"evidence_source"`
	CandidateVersion  string            `json:"candidate_version"`
	BuildDigest       string            `json:"build_digest"`
	Environment       string            `json:"environment"`
	RTCProviderRef    string            `json:"rtc_provider_ref"`
	VoiceProviderRef  string            `json:"voice_provider_ref"`
	RTCApplicationRef string            `json:"rtc_application_ref"`
	RegionRef         string            `json:"region_ref"`
	ChangeTicketRef   string            `json:"change_ticket_ref"`
	ExecutedByRef     string            `json:"executed_by_ref"`
	AttestedByRef     string            `json:"attested_by_ref"`
	AttestedAt        time.Time         `json:"attested_at"`
	CollectedAt       time.Time         `json:"collected_at"`
	Devices           []DeviceEvidence  `json:"devices"`
	Sessions          []SessionEvidence `json:"sessions"`
}

type DeviceEvidence struct {
	DeviceID         string `json:"device_id"`
	HardwareModel    string `json:"hardware_model"`
	HardwareRevision string `json:"hardware_revision"`
	FirmwareVersion  string `json:"firmware_version"`
	IdentityRef      string `json:"identity_ref"`
	AudioProfileRef  string `json:"audio_profile_ref"`
}

type SessionEvidence struct {
	ConversationID          string    `json:"conversation_id"`
	DeviceID                string    `json:"device_id"`
	EngineMode              string    `json:"engine_mode"`
	Scenario                string    `json:"scenario"`
	RoomRef                 string    `json:"room_ref"`
	DeviceRTCUserRef        string    `json:"device_rtc_user_ref"`
	AgentRTCUserRef         string    `json:"agent_rtc_user_ref"`
	ProviderTaskRef         string    `json:"provider_task_ref"`
	StartedAt               time.Time `json:"started_at"`
	EndedAt                 time.Time `json:"ended_at"`
	Lifecycle               []string  `json:"lifecycle"`
	RTCJoinSucceeded        bool      `json:"rtc_join_succeeded"`
	UplinkSucceeded         bool      `json:"uplink_succeeded"`
	DownlinkSucceeded       bool      `json:"downlink_succeeded"`
	NearAudioPublished      bool      `json:"near_audio_published"`
	FarAudioPlayed          bool      `json:"far_audio_played"`
	CredentialRenewed       bool      `json:"credential_renewed"`
	NetworkRecovered        bool      `json:"network_recovered"`
	ProviderStartAccepted   bool      `json:"provider_start_accepted"`
	ProviderStopConfirmed   bool      `json:"provider_stop_confirmed"`
	FinalTranscriptReceived bool      `json:"final_transcript_received"`
	UsageRecorded           bool      `json:"usage_recorded"`
	QualityResult           string    `json:"quality_result"`
	NoDuplicateProviderTask bool      `json:"no_duplicate_provider_task"`
	ResourcesReleased       bool      `json:"resources_released"`
	CloudEvidenceRef        string    `json:"cloud_evidence_ref"`
	DeviceEvidenceRef       string    `json:"device_evidence_ref"`
	ProviderEvidenceRef     string    `json:"provider_evidence_ref"`
	QualityEvidenceRef      string    `json:"quality_evidence_ref"`
	UsageEvidenceRef        string    `json:"usage_evidence_ref"`
}

type Check struct {
	Code   string `json:"code"`
	Status string `json:"status"`
	Detail string `json:"detail"`
}

type Report struct {
	SchemaVersion              string            `json:"schema_version"`
	Result                     string            `json:"result"`
	GeneratedAt                time.Time         `json:"generated_at"`
	CandidateVersion           string            `json:"candidate_version"`
	BuildDigest                string            `json:"build_digest"`
	EvidenceScope              string            `json:"evidence_scope"`
	ExternalValidationRequired bool              `json:"external_validation_required"`
	Environment                string            `json:"environment"`
	RTCProviderRef             string            `json:"rtc_provider_ref"`
	VoiceProviderRef           string            `json:"voice_provider_ref"`
	DeviceCount                int               `json:"device_count"`
	SessionCount               int               `json:"session_count"`
	CompletedEngineModes       []string          `json:"completed_engine_modes"`
	CompletedScenarios         []string          `json:"completed_scenarios"`
	ModeSessionCounts          map[string]int    `json:"mode_session_counts"`
	ScenarioSessionCounts      map[string]int    `json:"scenario_session_counts"`
	InputSHA256                map[string]string `json:"input_sha256"`
	Checks                     []Check           `json:"checks"`
	Disclaimer                 string            `json:"disclaimer"`
}

func ParseCapture(content []byte) (Capture, error) {
	var capture Capture
	if err := decodeStrict(content, &capture); err != nil {
		return Capture{}, fmt.Errorf("decode real device RTC capture: %w", err)
	}
	return capture, nil
}

func ParseReport(content []byte) (Report, error) {
	var report Report
	if err := decodeStrict(content, &report); err != nil {
		return Report{}, fmt.Errorf("decode real device RTC report: %w", err)
	}
	return report, nil
}

func Evaluate(capture Capture, candidateVersion, buildDigest string, generatedAt time.Time) Report {
	candidateVersion = strings.TrimSpace(candidateVersion)
	buildDigest = strings.ToLower(strings.TrimSpace(buildDigest))
	report := Report{
		SchemaVersion: ReportSchema, Result: "PASS", GeneratedAt: generatedAt.UTC(), CandidateVersion: candidateVersion, BuildDigest: buildDigest,
		EvidenceScope: "PROTOCOL_SIMULATION", ExternalValidationRequired: true, Environment: capture.Environment, RTCProviderRef: capture.RTCProviderRef, VoiceProviderRef: capture.VoiceProviderRef,
		DeviceCount: len(capture.Devices), SessionCount: len(capture.Sessions), CompletedEngineModes: []string{}, CompletedScenarios: []string{}, ModeSessionCounts: map[string]int{}, ScenarioSessionCounts: map[string]int{}, InputSHA256: map[string]string{}, Checks: []Check{},
		Disclaimer: "该报告只核对同一候选的终端、RTC、语音供应商、状态、媒体、字幕、用量、质量和回收证据；协议模拟不能替代量产终端与真实供应商验收，也不等于业务发布批准。",
	}
	if capture.EvidenceSource == "HARDWARE_PROVIDER_CAPTURE" {
		report.EvidenceScope = "REAL_DEVICE_RTC_PROVIDER"
	}
	add := func(code string, ok bool, detail string) {
		status := "PASS"
		if !ok {
			status, report.Result = "FAIL", "FAIL"
		}
		report.Checks = append(report.Checks, Check{Code: code, Status: status, Detail: detail})
	}
	add("CAPTURE_SCHEMA", capture.SchemaVersion == CaptureSchema, "RTC证据必须使用"+CaptureSchema)
	add("EVIDENCE_SOURCE", capture.EvidenceSource == "HARDWARE_PROVIDER_CAPTURE" || capture.EvidenceSource == "PROTOCOL_SIMULATION", "证据来源必须明确为HARDWARE_PROVIDER_CAPTURE或PROTOCOL_SIMULATION")
	add("CANDIDATE_IDENTITY", candidateVersion != "" && digestPattern.MatchString(buildDigest), "候选版本和sha256构建摘要必须完整")
	add("CAPTURE_CANDIDATE_BINDING", capture.CandidateVersion == candidateVersion && strings.ToLower(capture.BuildDigest) == buildDigest, "RTC采集必须绑定同一候选版本和构建摘要")

	real := capture.EvidenceSource == "HARDWARE_PROVIDER_CAPTURE"
	providerOK := capture.RTCProviderRef != "" && capture.VoiceProviderRef != "" && capture.RTCApplicationRef != "" && capture.RegionRef != ""
	environmentOK := capture.ExecutedByRef != "" && capture.AttestedByRef != "" && !capture.AttestedAt.IsZero() && !capture.CollectedAt.IsZero() && !capture.AttestedAt.After(capture.CollectedAt)
	if real {
		providerOK = providerOK && capture.RTCProviderRef != "mock" && capture.VoiceProviderRef != "mock"
		environmentOK = environmentOK && capture.ExecutedByRef != capture.AttestedByRef && (capture.Environment == "STAGING" || capture.Environment == "PRODUCTION") && capture.ChangeTicketRef != ""
	} else {
		environmentOK = environmentOK && capture.Environment == "LOCAL"
	}
	add("PROVIDER_IDENTITY", providerOK, "真实证据必须绑定非模拟RTC、语音供应商、应用和区域引用")
	add("ENVIRONMENT_IDENTITY", environmentOK, "真实证据必须绑定目标环境、变更工单、执行人和独立复核人")

	deviceOK := len(capture.Devices) > 0
	devices := map[string]bool{}
	for _, device := range capture.Devices {
		if device.DeviceID == "" || devices[device.DeviceID] || device.HardwareModel == "" || device.HardwareRevision == "" || device.FirmwareVersion == "" || device.IdentityRef == "" || device.AudioProfileRef == "" {
			deviceOK = false
		}
		devices[device.DeviceID] = true
	}
	if real && len(devices) < MinimumDevices {
		deviceOK = false
	}
	add("DEVICE_COVERAGE", deviceOK, "真实矩阵至少覆盖3台身份、硬件、固件和音频配置完整的候选终端")

	sessionOK, modeOK, scenarioOK, mediaOK, lifecycleOK, recoveryOK, providerLifecycleOK, dataOK, refsOK, timelineOK := len(capture.Sessions) > 0, true, true, true, true, true, true, true, true, true
	seenSessions, usedDevices := map[string]bool{}, map[string]bool{}
	normalModes := map[string]bool{}
	for _, session := range capture.Sessions {
		if session.ConversationID == "" || seenSessions[session.ConversationID] || !devices[session.DeviceID] || session.RoomRef == "" || session.DeviceRTCUserRef == "" || session.AgentRTCUserRef == "" || session.ProviderTaskRef == "" {
			sessionOK = false
		}
		seenSessions[session.ConversationID] = true
		usedDevices[session.DeviceID] = true
		if !slices.Contains(RequiredEngineModes, session.EngineMode) {
			modeOK = false
		} else {
			report.ModeSessionCounts[session.EngineMode]++
		}
		if !slices.Contains(RequiredScenarios, session.Scenario) {
			scenarioOK = false
		} else {
			report.ScenarioSessionCounts[session.Scenario]++
		}
		if session.Scenario == "NORMAL_COMPLETION" {
			normalModes[session.EngineMode] = true
		}
		mediaOK = mediaOK && session.RTCJoinSucceeded && session.UplinkSucceeded && session.DownlinkSucceeded && session.NearAudioPublished && session.FarAudioPlayed
		lifecycleOK = lifecycleOK && slices.Equal(session.Lifecycle, RequiredLifecycle)
		recoveryOK = recoveryOK && (session.Scenario != "TOKEN_RENEWAL" || session.CredentialRenewed) && (session.Scenario != "NETWORK_SWITCH_RECOVERY" || session.NetworkRecovered)
		providerLifecycleOK = providerLifecycleOK && session.ProviderStartAccepted && session.ProviderStopConfirmed && session.NoDuplicateProviderTask && session.ResourcesReleased
		dataOK = dataOK && session.FinalTranscriptReceived && session.UsageRecorded && session.QualityResult == "PASS"
		refsOK = refsOK && session.CloudEvidenceRef != "" && session.DeviceEvidenceRef != "" && session.ProviderEvidenceRef != "" && session.QualityEvidenceRef != "" && session.UsageEvidenceRef != ""
		timelineOK = timelineOK && !session.StartedAt.IsZero() && !session.EndedAt.IsZero() && !session.EndedAt.Before(session.StartedAt) && !session.EndedAt.After(capture.CollectedAt)
	}
	if real {
		sessionOK = sessionOK && len(capture.Sessions) >= MinimumSessions && len(usedDevices) >= MinimumDevices
		for _, mode := range RequiredEngineModes {
			if report.ModeSessionCounts[mode] == 0 || !normalModes[mode] {
				modeOK = false
			}
		}
		for _, scenario := range RequiredScenarios {
			if report.ScenarioSessionCounts[scenario] == 0 {
				scenarioOK = false
			}
		}
	}
	for _, mode := range RequiredEngineModes {
		if report.ModeSessionCounts[mode] > 0 {
			report.CompletedEngineModes = append(report.CompletedEngineModes, mode)
		}
	}
	for _, scenario := range RequiredScenarios {
		if report.ScenarioSessionCounts[scenario] > 0 {
			report.CompletedScenarios = append(report.CompletedScenarios, scenario)
		}
	}
	add("SESSION_IDENTITY", sessionOK, "真实矩阵至少6通且会话、设备、房间、用户和供应商任务引用必须唯一完整")
	add("ENGINE_MODE_COVERAGE", modeOK, "三种语音方式均须完成正常闭环")
	add("SCENARIO_COVERAGE", scenarioOK, "矩阵须覆盖正常完成、凭证续签、网络切换恢复和受控停止")
	add("RTC_MEDIA_PATH", mediaOK, "每通必须入房成功并证明上行、下行、近端发布和远端播放")
	add("STATE_LIFECYCLE", lifecycleOK, "每通必须按ROOM_ISSUED到COMPLETED的受控状态序列收敛")
	add("TOKEN_NETWORK_RECOVERY", recoveryOK, "对应场景必须证明短期凭证续签或网络切换恢复")
	add("PROVIDER_LIFECYCLE", providerLifecycleOK, "供应商启停、任务去重和RTC资源回收必须完成")
	add("TRANSCRIPT_USAGE_QUALITY", dataOK, "每通必须形成最终字幕、用量记录和业务方质量通过结论")
	add("EVIDENCE_REFERENCES", refsOK, "每通必须保存云端、设备、供应商、质量和用量脱敏引用")
	add("EXECUTION_TIMELINE", timelineOK, "每通开始结束时间必须有效且不晚于采集时间")
	if real && providerOK && environmentOK && deviceOK && sessionOK && modeOK && scenarioOK && mediaOK && lifecycleOK && recoveryOK && providerLifecycleOK && dataOK && refsOK && timelineOK && report.Result == "PASS" {
		report.ExternalValidationRequired = false
	}
	return report
}

func SHA256(content []byte) string {
	digest := sha256.Sum256(content)
	return hex.EncodeToString(digest[:])
}

func decodeStrict(content []byte, target any) error {
	decoder := json.NewDecoder(bytes.NewReader(content))
	decoder.DisallowUnknownFields()
	if err := decoder.Decode(target); err != nil {
		return err
	}
	var trailing any
	if err := decoder.Decode(&trailing); !errors.Is(err, io.EOF) {
		return errors.New("trailing JSON data")
	}
	return nil
}